The present invention relates to fiberoptic network devices and, more particularly, to laser source assemblies.
In fiber optics, lasers provide the only practical source of light signals for the optical fibers. In a fiberoptic network, semiconductor lasers are used as sources for the light signals of the network. The sources are typically formed from a laser diode chip which is mounted in a hermetically sealed package.
Recently some fiberoptic device manufacturers have attached a fiber grating to the output fiber of laser diode packages. The fiber grating narrows the linewidth of the laser diode output. Sources with narrow linewidths are desirable in certain applications, such as for WDM (Wavelength Division Multiplexing) networks. A particularly suitable application is the stabilization of pumping sources of EDFA's (erbium-doped fiber amplifiers) for high gain conversion efficiency and gain stability. However, the inventors of the present invention have determined problems with this arrangement, including adverse effects upon the lifetime of the laser diode.
The present invention solves or substantially mitigates these problems.